The religious authority Carl must petition for permission for Emberus to break the gods-demons truce.
The High Cleric of the Watch is the figure Emberus's quest update sends Carl to treat with at the Temple of Issitoq, reachable in a Club Vanquisher. Emberus needs formal permission to break the truce between the gods and the demons of Sheol — so that he can accept Amayon's bargain and learn who killed his son — without triggering a war that would burn the mortal world to ashes, and the High Cleric evidently holds the authority to grant that dispensation.
Carl receives the instruction during The Ceasefire, has no idea what to make of it, and defers it as a tomorrow problem.
Gatekeeper of divine permission to break the gods' truce with the demons.